The pueblo builder has never been able to construct a detached chimney a full story in height, either with or without the aid of chimney pots; where it is necessary to build such shafts to obtain the proper draft he is compelled to rely on the support of adjoining walls, and usually seeks a corner. Pl. CI shows a chimney of this kind that has been built of masonry to the full height of a story. A similar example is shown in the foreground of Pl. LXXVIII. In Pl. XXII may be seen a chimney of the full height of the adjoining story, but in this instance it is constructed wholly of pots. Pl. LXXXV illustrates a similar case indoors. The external chimney probably developed gradually from the simple roof opening, as previously noted. The raised combing about trapdoors or roof holes afforded the first suggestion in this direction. From this developed the square chimney, and finally the tall round shaft, crowned with a series of pots. The whole chimney, both internal and external, excluding only the primitive fireplace, is probably of comparatively recent origin, and based on the foreign (Spanish) suggestion. GATEWAYS AND COVERED PASSAGES. Gateways, arranged for defense, occur in many of the more compactly-built ancient pueblos. Some of the passageways in the modern villages of Tusayan and Cibola resemble these older examples, but most of the narrow passages, giving access to the inner courts of the inhabited villages, are not the result of the defensive idea, but are formed by the crowding together of the dwellings. They occur, as a rule, within the pueblo and not upon its periphery. Many of the terraces now face outward and are reached from the outside of the pueblo, being in marked contrast to the early arrangement, in which narrow passages to inclose courts were exclusively used for access. In the ground plans of several villages occupied within historic times, but now ruined, vestiges of openings arranged on the original defensive plan may be traced. About midway on the northeast side of Awatubi fragments of a standing wall were seen, apparently the two sides of a passageway to the inclosed court of the pueblo. The masonry is much broken down, however, and no indication is afforded of the treatment adopted, nor do the remains indicate whether this entrance was originally covered or not. It is illustrated in Pl. CII. [Illustration: Plate LXXXVIII. North kivas of Shumopavi, from the northeast.] Other examples of this feature may be seen in the ground plans of Tebugkihu, Chukubi, and Payupki (Fig. 7, and Pls. XII and XIII).